The Anonymous hacker group says it took the Visa website down on Wednesday in retaliation for the credit card company suspending payments to the Wikileaks site, with Facebook and Twitter removing the group's accounts.

The group hit the MasterCard site with a distributed denial-of-service attack for the same reason, and it took down PayPal over the weekend. The MasterCard site was back up this afternoon. Visa said on Tuesday that it was suspending payments to the controversial whistleblower site, joining MasterCard and PayPal.

Operation Payback also said its page had been banned from Facebook for violating terms of use, and the group's Twitter account was suspended as well. Attempts to reach the group's Twitter page displayed a warning that said "Sorry, the profile you are trying to view has been suspended". A Twitter representative declined to comment on the matter. The group then created at least one new account on Twitter after being suspended.